1. Field of the Invention
The present invention relates to an electromagnetic wave shield box that receives a wireless terminal, such as a mobile phone, in order to perform an operation test of the wireless terminal, and, more particularly, to an electromagnetic wave shield box that is capable of providing receiving and loading positions to accomplish optimum positional relations between a coupling antenna disposed in the box and antennas of various types of wireless terminals whose antennas, including an inner-type antenna, are located at different positions, and of securing the reproducibility thereof.
2. Description of the Related Art
When a wireless terminal, such as a mobile phone, is bought or even after the wireless terminal is bought, it may be necessary to confirm whether or not the signal transmission state and the signal reception state of the wireless terminal are normal during use of the wireless terminal. For this reason, every mobile phone store usually has a tester to easily test the operation of the wireless terminal.
When the operation of the wireless terminal is tested using such a tester, an electromagnetic wave shield box, which allows the wireless terminal to be disposed in a space shielded from electromagnetic waves outside the electromagnetic wave shield box, is used to prevent the external electromagnetic waves from being introduced into an antenna of the wireless terminal to be tested such that the test results are not affected by the external electromagnetic waves.
Japanese Unexamined Patent Publication No. 2004-80271 discloses an example of electromagnetic wave shield box, which has been previously proposed by the applicant of the present application. According to the disclosure of the above-mentioned patent publication, the same type of wireless terminal is disposed at a predetermined position in the electromagnetic wave shield box, and a loading table (holder) for positioning the wireless terminal at a predetermined position in the electromagnetic wave shield box to obtain the reproducibility in the position during the test. This loading table includes a groove-shaped loading unit mounted at a predetermined position of a board fixed in the electromagnetic wave shield box such that the loading unit corresponds to the outer appearance of a folder type wireless terminal, and contact means mounted at a predetermined position adjacent to the loading unit, the contact unit being formed in the shape of a predetermined block, whereby the wireless terminal is securely disposed at a specific position in a predetermined posture in the electromagnetic wave shield box while the wireless terminal is opened in a predetermined manner, and therefore, the positional relation between the wireless terminal and a coupling antenna mounted at a predetermined position in the electromagnetic wave shield box is fixed. Furthermore, a cover, which is constructed to be openable and closable, is connected to a box body of the electromagnetic wave shield box for shielding the wireless terminal from external electromagnetic waves.
In order to perform the operation test of a wireless terminal using the above-mentioned electromagnetic wave shield box, the cover is opened, the wireless terminal, which is an object to be tested, is disposed at a predetermined position in the electromagnetic wave shield box, and the cover is closed. As a result, the wireless terminal is received in the electromagnetic wave shield box while the wireless terminal is shielded from electromagnetic waves outside the electromagnetic wave shield box, and the positional relation between the wireless terminal and the coupling antenna in the electromagnetic wave shield box is fixed. During the operation test of the wireless terminal, a radio frequency (RF) signal is transmitted from a tester located outside the electromagnetic wave shield box to the electromagnetic wave shield box such that electric waves are emitted from the coupling antenna, and the signal reception state of the wireless terminal is confirmed by the tester outside the electromagnetic wave shield box via a control line connected to the wireless terminal.
According to the above-described electromagnetic wave shield box, in the case that the wireless terminal is tested while the wireless terminal is received in the electromagnetic wave shield box, it is possible to set the position of the antenna of the wireless terminal with respect to the coupling antenna mounted in the electromagnetic wave shield box such that the same positional relation is always maintained at the position where the operational performance of the wireless terminal is the best so long as the same type of wireless terminal is tested, and therefore, it is possible to accurately perform the operation test of the wireless terminal.
As described above, according to the above-described conventional electromagnetic wave shield box, in the case of the same type of wireless terminal, the antenna of which is mounted at a predetermined position, the wireless terminal can be attached to a specific attachment position with respect to the electromagnetic wave shield box, and therefore, the positional relation between the wireless terminal and the coupling antenna mounted in the electromagnetic wave shield box is fixed. In the case of various different types of wireless terminals, whose antennas are located at different positions, however, the optimum positional relation, in which the operational performance of the wireless terminal is the best, is different for each wireless terminal. As a result, it is not possible to accurately perform the operation test of the wireless terminal using the above-described conventional electromagnetic wave shield box.
For example, a large number of mobile phones have an inner-type antenna, which is mounted in a body case of each mobile phone in addition to an telescopic-type antenna, which can be manipulated outside each mobile phone. In recent years, some types of mobile phones have been provided with only the inner-type antenna. The position of the inner-type antenna in the body case is different according to types of mobile phones, and it is difficult to confirm the position of the inner-type antenna only by viewing the outer appearance of the mobile phone. Consequently, even though the structure for positioning the body case of the mobile phone at a predetermined position in the electromagnetic wave shield box like the above-described electromagnetic wave shield box is adopted, the positional relation between the inner-type antenna of the mobile phone and the coupling antenna at the electromagnetic wave shield box is not always optimum if the type of mobile phone is different, and therefore, the test condition is changed depending upon the type of mobile phone.
For this reason, it may be possible to provide exclusive holders for positioning the respective different types of mobile phones, whose antennas are located at different positions, in the electromagnetic wave shield box, and to obviously set the positions where all types of mobile phones are disposed in the electromagnetic wave shield box. According to this method, the positional relation between the inner-type antenna and the coupling antenna of the electromagnetic wave shield box is fixed irrespective of the types of mobile phones, and it is possible to obtain optimum test conditions for any type of mobile phone. However, there are many different types of mobile phones, and it is very troublesome to prepare exclusive holders for the respective types of mobile phones and to install the exclusive holders in the respective mobile phone stores. Furthermore, a great deal of costs are necessary.